Buy the gun not the name. Lang, like most makers could and would make any quality level gun the buyer had money to purchase. Some may have been Birmmy guns brought in in the white and finished up in the lowest grades. That's why you see different guns that are all over the place quality wise. But even the lowest was a solid gun that has lasted a hundred years. But after a hundred years there is a lot of wear and "repairs" which need to be evaluated by a good double gunsmith.
So buy the gun not the name. Barrels first thing I look at, on face second, wear and function, wood and engraving last. Order is subjective but they all need to be looked at before the checkbook comes out.